Condensation-crosslinking silicone materials

Abstract

Materials crosslinkable at room temperature by condensation are based on organosilicon compounds which cure to give permanently resilient materials, and which employ one or more compounds of the metals Li, Na, K, Mg, Ca, or Sr as catalyst.

1. A condensation-crosslinking silicone composition comprising
 (A) 100 parts of at least one organosilicon compound having at least 2 condensable groups, 
 (B) 1-10 parts of at least one crosslinking agent selected from the group consisting of tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-cyanopropyltrimethoxysilane, 3-cyanopropyltriethoxysilane, 3-(glycidyloxy)propyltriethoxysilane, 1,2-bis(trimethoxysilyl)ethane, 1,2-bis(triethoxysilyl)ethane, methyltris(methylethylketoximo)silane, vinyltris(methylethylketoximo)silane, tetrakis(methylethylketoximo)silane, partial mixed hydrolyzates thereof, and mixtures thereof, 
 (C) at least one filler, 
 (D) 0.1-50 parts of at least one adhesion promoter selected from the group consisting of a hydrolyzable alkoxysilane bearing vinyl, epoxy, amino, (meth)acryloyloxy, acid anhydride, acid, ester or ether groups and mixed hydrolyzates thereof, and 
 (E) at least one catalyst in a catalytic amount, selected from the group consisting of carboxylates of the metal Sr, and 
 wherein the composition is free of organotin compounds. 
 
     
     
       2. A process for the preparation of a composition of  claim 1 , comprising mixing all constituents with one another. 
     
     
       3. An adhesive, sealing compound, coating, or potting composition comprising a condensation-crosslinking silicone composition of  claim 1 . 
     
     
       4. The composition of  claim 1 , which is free of titanium metal catalysts. 
     
     
       5. The composition of  claim 1 , wherein at least one adhesion promoter (D) is 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, or a mixture thereof. 
     
     
       6. A condensation-crosslinking silicone composition comprising
 (A) at least one organosilicon compound having at least 2 condensable groups, 
 (B) at least one crosslinking agent, 
 (C) at least one filler, 
 (E) at least one catalyst in a catalytic amount, selected from the group consisting of carboxylates of the metal Sr, and 
 wherein a mixture of Li compounds and Sr carboxylates are used as catalyst (E); and 
 wherein the composition is free of organotin compounds. 
 
     
     
       7. A condensation-crosslinking silicone composition comprising
 (A) at least one organosilicon compound having at least 2 condensable groups, 
 (B) at least one crosslinking agent, 
 (C) at least one filler, 
 (E) at least one catalyst in a catalytic amount, selected from the group consisting of carboxylates of the metal Sr, and 
 wherein the catalyst(s) (E) are the sole catalysts, 
 and wherein the composition is free of organotin compounds. 
 
     
     
       8. The composition of  claim 7 , which is free of titanium metal catalysts.